///2017 Abstract Details
2017 Abstract Details2019-08-02T15:54:53-06:00

Assessment of Thromboelastography in Patients with Factor XI Deficiency

Abstract Number: F-24
Abstract Type: Original Research

Nathan W Liu MD1 ; Laura L Sorabella MD2; Justin K Stiles MD3; Jessica L Geerling MD4; Yunping Li MD5; Philip E Hess MD6


Factor XI (FXI) deficiency manifests with varying degrees of severity, but plasma levels do not correlate with bleeding risk.(1) Improved prenatal screening with gene chips has led to the detection of patients with heterozygous deficiency (hFXI). Although these patients may have very low plasma concentrations of FXI, no guidance for regional anesthesia exists. We investigated thromboelastography (TEG) in the clinical management of pregnant patients with confirmed hFXI.


FXI levels and TEG studies were obtained on third trimester patients diagnosed with hFXI as detected by first trimester prenatal genetic screening. 15 patients were identified and enrolled between 2014-2017. 15 healthy parturients matched for age and gestational age were enrolled as control subjects. Parturients were followed peripartum to determine type of labor analgesia offered, mode of delivery, and occurrence of any postpartum complications.


Patients with hFXI deficiency demonstrated a longer time to fibrin formation (R time; Table); however, R was within normal control in all but one patient. There were no other significant differences in subsequent TEG parameters when compared to control curves. FXI levels were lower in the hFXI group (Table) compared to controls, but did not correlate with R time. All patients in the study and control groups safely received neuraxial analgesia or anesthesia for delivery. There were no instances in which prophylaxis (e.g. tranexamic acid, fresh frozen plasma, Factor XI concentrate) was required prior to neuraxial instrumentation. No anesthesia-related complications or significant postpartum bleeding occurred.


Our hFXI patients had subnormal factor plasma levels into the third trimester, but TEG values were on the higher side of normal. We observed a longer (but within normal) R time on TEG in patients with hFXI, but R time did not correlate with degree of factor deficiency. This parallels previous findings in third trimester parturients using ROTEM, which demonstrated a longer CT value.(2) There were no differences in remaining TEG parameters between patients with hFXI and controls. We believe this data suggest that heterozygous patients are safe for neuraxial anesthesia, and that TEG provides an additional means to assess global coagulation in parturients with Factor XI deficiency prior to safe delivery of anesthesia.

1. Haemophilia. 2016, vol. 22, 188.

2. Haemophilia. 2016, vol. 22, 276.

SOAP 2017